Many people use rebounds relationships as a way to distract themselves from pain and to move on as quickly as possible. But according to April Davis, professional matchmaker and founder of LUMA - Luxury Matchmaking, jumping into another relationship right after you got out of one could mean that you haven't had time to fully heal from heartbreak.

"If you see your new partner as a rebound and then you see your ex move on to a new relationship, that would hurt because you may still have feelings for your ex," Davis says. Even if it looks like you've moved on, there’s a chance you really haven't. "Seeing your ex move on would result in you being just as hurt as if you were still single," she says.

In some cases, the "pain" you feel when your ex moves on might not have anything to do with having lingering feelings for them. It may just be your ego getting bruised. "Ego can play a big role in feeling hurt," Davis says. "Some people like the idea of someone having feelings for them even if they don't reciprocate it back. It makes them feel wanted." There's comfort in thinking there's someone out there who's still hung up on you. And seeing your ex with someone else can ruin the illusion you created for yourself.

It's also human nature to compare yourself to the new person your ex is with, which can make you question yourself. What do they have that you don’t? Are they better looking? Better in bed? Do their personalities mesh better? Do they get along with your ex’s friends more? It’s easy to get lost social media stalking your ex’s new partner and feeling bad about yourself in the process. As Kevin Darné, relationship expert and author of My Cat Won't Bark! (A Relationship Epiphany), tells Bustle, "One of the worst feelings is for some people to see their ex seemingly stepping up or doing better after a breakup."

Your first love may not be the love of your life, but it's still hard to forget what you had with them. Your ex may have been the first person who’s ever made you feel safe. Because of that, you were able to share aspects of your life that you’ve never shared with anyone before — and that’s always going to stick with you.

According to Davis, some people feel protective over their first loves long after the relationship is over. "Since you 'got there first' you might have a slight feeling of possession over them," Davis says. "So when you see them with someone new, even if you don't want them back, you might feel that the new person shouldn't have, or doesn't deserve your ex."

If someone meant a lot to you, it’s only natural to want them to feel the same way about you. Seeing your ex with someone else may trigger doubts and insecurities over how your partner truly felt about you in the relationship. Even if you want your ex to be happy now, it’s normal to question whether they truly loved you as much as they said they did.

"The opposite of love is not hate, it's indifference," Darné says. "We want to believe that if we bump into our ex there'll be an awkward pause or an uneasy feeling. A lack of jealousy or envy on the part of someone's ex can have a negative effect on some people." It doesn't matter if you're already in another relationship now. When you see a picture of your ex smiling with their new partner, it may lead you to question why they never looked as happy when they were with you.

When you invest time and energy into trying to make a relationship work, it can make you feel like a complete failure when it doesn't. According to Dr. Caroline Madden, PhD, licensed marriage and family therapist, seeing your ex happy with someone else can be a reminder of that. It's easy to forget why you broke up and place all the blame on yourself. "Keep in mind that everyone looks happy in the first part of a relationship,” Madden says.

In addition to making you feel like a failure, a breakup can also feel like a loss. According to Heidi Krantz, certified dating and relationship coach, seeing your ex with someone else is “like the loss of your dream hitting you in the face.”

It may have been years since you’ve last seen your ex. And you may feel like you’ve moved on, and that your current relationship status shows it. But, in some cases, feeling hurt over seeing your ex with someone new could indicate that you still need a little more time to fully heal.

"Just because you moved on, doesn't mean the remorse or grief over the dissolved relationship totally disappears," Laurie Berzack, MSW, matchmaker and dating coach, tells Bustle. "You may still be grieving a relationship that you were once attached to." Everyone deals with a breakup and moves on at their own pace. Taking some time to clear out negative feelings towards your ex and your past relationship can help you fully heal and move forward with your current one.

Special moments are considered sacred for a reason. You want to feel like certain memories, places, or words said were meant for you and only you. Nobody wants to feel like they’re just another ex. And the idea of your ex having fun experiences and creating new memories with someone else can make you feel sad, Samantha Daniels, relationship expert and founder of Samantha’s Table Matchmaking tells Bustle. “The two of you had a lot of good times together and it’s hard to imagine them doing it with someone else,” Daniels says.

After a breakup, there may be a small part of you that hopes you move on faster than your partner. According to Alexis Wolfe, a dating expert and founder of NYCDateNite, seeing your ex with someone else may make you wonder how well you’re doing in comparison to your ex. This can happen if you have yet to find a new partner yourself. You may wonder why you haven’t found someone, or question your decision to break up.

“It can make you feel inadequate,” Wolfe says. “With your ex moving on, it forces you to come to terms with the relationship being officially over and that chapter of your life totally closed. Breakups are a roller coaster of emotions and sometimes the fact that it’s over doesn’t totally hit someone until the other person finds another partner. Endings are hard and it is usually difficult to watch someone you love to move on with their life.”

It can be a little confusing to feel pain after seeing your ex with someone new, especially when you’ve moved on and are already with someone else. But it's a completely common reaction. As Toni Falcone, Psy.D., licensed psychologist who specializes in relationships, tells Bustle, "Attributing extra meaning to a normal reaction is a primary contributor to the pain (and stress) often associated with this experience.” Falcone says. “Just because it feels icky or it hurts to see your ex move on, doesn’t mean you still love them or want to be with them."